Over the years considerable technology has developed around the solution to the problem of pacifying babies and small children. Generally, infantile unrest and later, the hyperactivity of small children, are naturally occurring phenomena which, to greater and lesser extents, appear to be "programmed into" human beings from birth. In particular, the response of infants to the outside world appears to be calculated to stimulate the sort of parental attention which would certainly have been required in the relatively dangerous environment in which man evolved.
Thus the classic pattern appears. An abandoned child cries, signalling his mother to devote some attention to him either in the form of hugging, cuddling, nursing or the like. Upon the application of one of these stimuli, the crying usually stops.
Above and beyond this it has been found in research with the related species that withholding such stimuli can have permanent adverse effects on personality development and the mental stability of the adult animal. Controlled studies have shown, for example, that primates brought up in sterile laboratory surroundings without any objects around them have been found to be significantly disadvantaged as compared to other animals of the same species which were provided with a form which they could hug and which included structure which they could protect themselves in.
While such work is relatively recent, most successful infant pacifiers have always simulated otherwise naturally occurring human interactions. A few examples of such devices include milk bottles, nipple pacifiers, and soft dolls. In the case of somewhat older children one may also add pets and a different class of devices calculated to stimulate and interest the mind of the child. Such devices include crib chimes, animated dolls, talking dolls and the like.
While all of the above devices do perform the desired function of pacifying children, they all suffer from various inadequacies. For example, nipple pacifiers, while they are quite inexpensive and may intially be effective, do essentially frustrate the natural expectations of the infact and, after a short time, are recognized and rejected. Stuffed toy animals, while soft and appealing in texture, are essentially passive and thus, particularly in the case of infants, are not very effective as the infant is unable to fully comprehend the device. To a limited extent the device can be improved by incorporating an audio device (such as a tape recorder) in a toy doll to add an audio stimulus to such a pacifier. However, the stimulus is extremely complicated and not of a type likely to be understood or learned by a small infant. In addition, in the case of smaller children, talking dolls are likely to have the opposite of the desired effect, that is stimulating activity, instead of providing a calming influence. In addition, such talking dolls are likely to be expensive and complicated devices which are highly subject to breakdowns and sensitive to the abuse likely to be given to them by children.